Answer to Question #255396 in Inorganic Chemistry for shamsa

Question

7. Based on Coulomb's Law V=keq1q2r how we can make comparison between ionization energy of Rubidium (Rb) and Krypton (Kr)? A. The ionization energy of Rb is larger than Kr, which is consistent with the increase in the charge. B. The ionization energy of Kr is larger than Rb, which would require the size to increase. C. The ionization energy of Kr is larger than Rb, but since both charge and radius are responsible for ionization energy, no certain conclusion about the size can be made. D. The ionization energy of Rb is larger than Kr, which would require the size to decrease.

Answer 1

imagine Kr as a Rb inner shell with a few extra protons in the nucleus and a corresponding number of extra electrons in the outer shells, but of course the extra protons shrink the “Rb core” before the extra electrons go on, and the s-electrons that go on first are spending a lot of time commingling with the electrons of the “Rb core”. However, the last electrons are nearly in Rydberg states, so if you’re allowed to know the empirical “size” of both atoms you could just pretend that the last electron on each goes into a circular orbit about a single positive charge at that radius…